What are the ordered pairs of y= 3x - 1 (4,13)

Question

I need to learn how to do this so I can take a test by tomorrow

Answer 1

y= 3x - 1     Set up a table of values.

 

    x      y   

   -4   -13         y = 3(-4) - 1 = -13

   -3   -10         y = 3(-3) - 1 = -10

   -2   -7           y = 3(-2) - 1 = -7

   -1   -4           y = 3(-1) - 1 = -4

    0   -1           y = 3(0) - 1 = -1

    1    2            y = 3(1) - 1 = 2

    2    5            y = 3(2) - 1 = 5

    3    8

    4   11         and so forth 

 

Notice that every time x increases by 1, y increases by 3 because the slope is 3. 

Answer 2

Recheck your question.

Why do I ask? because when I substitute x=4 and y=13 into the original equation I get

 

 y= 3x - 1 (4,13) 

13= 3(4) - 1

13= 12 - 1

13=11 which is incorrect

 

So let's say the correct equation is 

 

y=3x+1 (4,13)

 

13= 3(4)+1

13=12+1

13=13   Correct 

 

Good. Now we know the correct Equation.

y=3x+1 (4,13)

 

 

Let's solve for x.
y=3x+1
Step 1: Flip the equation.
3x+1=y
Step 2: Add -1 to both sides.
3x+1+−1=y+−1
3x=y−1
Step 3: Divide both sides by 3.
3x/3= (y−1)/3


Answer:
x=(y−1)/3

Answer 3

y= 3x - 1

 

It's easy.  Pick any value of x, say x=1, and plug that value into the equation and compute the y value:

    y = 3x + 1

    y = 3·1 + 1    (plugged in 1 for x)

    y = 3 + 1

    y = 4

 

So the ordered pair is (1, 4).  The first number is the x, the second is the y.  For x = -2, we get:

    y = 3x + 1
    y = 3·(-2) + 1    (plugged in -2 for x)
    y = -6 + 1
    y = -5

 

So the ordered pair is (-2,-5).  If they give you an ordered pair and ask if it is an ordered pair of the equation, just plug in the x value and see if you compute the same y value that they give.  If it does, it's a solution; otherwise it isn't.  For example, is (0, 5) an ordered pair of y = 3x + 1?

    y = 3x + 1

    y = 3·0 + 1

    y = 0 + 1

    y = 1

 

No, we got y = 1 not y=5, so (0,5) is not an ordered pair of y = 3x+1.